This study examined intrajudge and interjudge agreement for the Lidcombe Behavioral Data Language (LBDL), a behaviorally based stuttering taxonomy. Ten experienced speech language pathologists and 10 undergraduates applied the LBDL to stuttered speech on two occasions. Intrajudge agreement was high for both groups, but only the experienced judges achieved interjudge agreement. Results suggest some stuttering behaviors may be difficult to categorize. (Contains references.) (Author/DB)